Push button retention and release mechanism



1968 T. PIOTROWSKI 3,

PUSH BUTTON RETENTION AND RELEASE MECHANISM Filed Jan. 10, 1967INVENTOR. TADEUS momowsm AGEN T United States Patent 0 3,416,388 PUSHBUTTON RETENTION AND RELEASE MECHANISM Tadeus Piotrowski, Vienna,Austria, assignor to North American Philips Co., Inc., New York, N.Y., acorporation of Delaware Filed Jan. 10, 1967, Ser. No. 608,368 Claimspriority, application Austria, Jan. 14, 1966, A 327/66 4 Claims. (Cl.74-483) ABSTRACT OF THE DISCLOSURE The push button switch mechanismdisclosed comprises a series of selectively operative push buttons whichswitch on and operate a particular device while locked in a depressedposition and a release push button that when depressed mechanicallyreleases said operative push buttons from the locked position andthereby discontinues the operation of said device. The series ofoperative push buttons are typified by a spring biased push button whichis movably retained in a first support plate and which lockingly engagesa holding beam when depressed through the cooperation of a catch on thepush button and a spring bias mechanism coacting with the holding beamand the push button. The release push button coacts with the holdingbeam to return the beam to its original position and thereby release thelocked push buttons.

The invention relates to a push button mechanism which is generallyapplicable to recording and play-back apparatus. In such apparatus, itis often desirable to lock one or more push button elements intooperative position and to restrict the movement of the remaining pushbuttons so that these latter buttons cannot be operated withoutreleasing the already engaged push buttons.

It is an object of this invention to provide a simple position lockingmechanism for push button units.

A further object of the invention is to provide a push button unitwherein the remaining push buttons may not be activated after theinitial push buttons have been depressed and lockingly engaged.

Another object of the invention is to provide a push button having anovel mechanism for releasing the lockingly engaged push buttons.

The invention also provides a push button mechanism in which thefunctions of holding, locking and releasing the keys thereof areachieved in a simple and economic manner. This mechanism also ensuresreliable operation over a sustained period of use.

In accordance with the invention, the foregoing objects are achieved bya push button mechanism in which at least one push button can be held inan operating position by a spring biased holding beam. The push buttonsinclude a surface which cooperates with the holding beam wherebydepression of the push button moves the holding beam in a directionnormal to the movement of the push button and into locking engagementwith a catch element on the push button. A spring biasing mechanismattached to the holding beam causes the holding beam to be biased in theengagement position.

An auxiliary push button for releasing the lockingly engaged pushbuttons is also part of the push button mechanism. This release pushbutton engages the holding beam while it is lockingly engaged with atleast one operatively depressed push button and forcibly returns theholding beam, by overcoming the biasing engagement force, into its restposition and thereby releases the depressed push button. The pushbuttons are spring biased with the biasing force acting to return thepush buttons to an inoperative position.

r 3,416,388 Ice Patented Dec. 17, 1968 The invention will be describedin greater detail with reference to the accompanying drawing, in which:

FIGURE 1 is a cross-sectional view of a push button unit in accordancewith one embodiment of the invention;

FIGURE 2 is a cross-sectional view of a push button mechanism inaccordance with a second embodiment of the invention.

Referring now to FIGURE 1, the mechanism there shown comprises a supportmember 1 in which the push buttons are arranged so as to be movableagainst the action of the springs 2. Guide members 3 are located at eachend of the support 1. A holding beam 4 is in movable engagement with theguide members 3. A tension spring 5 is fastened to one end of theholding beam and to a rigid portion of the device in which the pushbutton mechanism or unit is attached and normally tends to move the beam4 to the right, i.e. in the direction of the arrow 20 and therebydetermines the rest position of the holding beam 4. Recesses 6 withinthe holding beam 4 receive the control elements of the push buttons. Theseries of engaging push buttons are duplicates and are generally shownin FIGURE 1 as operative push button 8. The push button 8 is constructedwith a catch element 10 such that the button in the depressed positionwill be fixedly held in that position by engagement of the catch 10 andthe edge of the recess 6 on the holding beam 4. Each of the buttons 8 isappropriately mechanically connected to the element (i.e. electricswitch etc. not shown) to be activated thereby. This may be effected forexample, by a suitable mechanical linkage (not shown) engaging the slot21 of the element 10.

Adjacent the edge of the recess 6 opposite the edge which engages thecatch 10 and fastened to the holding beam 4 is a resilient or biasingmechanism 11. This mechanism includes a guided slide element 13 which isbiased by a compressing spring 12. The slide 13 is movable to a limitedextent as determined by the extent of a slot 22 in a direction parallelto the longitudinal axis of the holding beam and is slidably engageablewith the inclined surface 14 on the operative push button controlelement 7. Depressing the operative push button 8 causes the inclinedsurface 14 to engage the end of slide 13 and move it to the left asshown in FIGURE 1 thereby compressing the spring 12. The tension spring5 and the compression spring 12 act in opposition. Spring 12 isconstructed so that when compressed a predetermined amount, the force ofcompression will exceed the restraint applied by the tension spring 5and thereby cause the holding beam to move towards the left.

In FIGURE 1, the operative push button 8 is shown in a partiallydepressed position. Further depression will compress the spring 12causing movement of the holding beam in the manner described above. Whenthe catch 10 on the control element 7 passes through the opening 6, theholding beam will move into overlying locking engagement with the catch10 with the spring 12 biasing the holding beam in this position. Thus,upon releasing the push button it will remain depressed and in lockedengagement with holding beam 4.

One or more push buttons 8 can be depressed; however, when a pluralityof the buttons are to be depressed, depression must occur simultaneouslyin order to properly engage the holding beam. Once a push button hasbeen depressed and has lockingly engaged the holding beam, no additionalpush buttons may be depressed without release of the originally lockedbuttons, because the holding beam 4 is prevented from traveling to theleft (i.e. against the direction of the arrow 20) by the biasingmechanism which forces the holding beam into engagement with the pushbutton to an extent sufiicient to allow the passage of the saidadditional button through the holding beam 4.

A single push button 9 is incorporated in the push button unit forreleasing one or more of the depressed, locked operative push buttons 8.Release is effected by moving the holding beam 4 towards its originalrest position. This is accomplished by opposing the biasing forceapplied by the biasing mechanism 11. The control element 7 of pushbutton 9 has an inclined cam surface 14a which engages the edge 15 ofthe opening 6 when the release push button is depressed. The engagementbetween the cam surface 14a and edge 15 causes the holding beam 4 tomove towards the right or to the original rest position of the holdingbeam 4. This movement causes the release of the catch 10 by the holdingbeam 4 wherein the compressed spring 2 will cause the push button 8 toreturn to its inoperative position.

The holding beam 4 remains permanently displaced once one or more pushbuttons 8 have been depressed. Extension element 16 at the base of thecatch 10 will abut the upper surface of the holding beam 4 if actuationof an additional operative push button 8 should be attempted after atleast one operative push button is in depressed locked engagement.Therefore, other push buttons 8 can be depressed only if the holdingbeam 4 has been returned to its original rest position by means of therelease push button 9. This is of particular importance in recording andplay-back apparatus in which the switching from one operation or mode ofoperation to a second operation or mode must be accomplished via a restposition.

The embodiment of FIGURE 2 uses the same reference characters as FIGURE1 for denoting similar components. In this particular embodiment two ofthe operative push buttons 8 and the one release push button 9 areshown. One of said push buttons 8 being shown in the non-depressedposition and the second push button 8 being shown in the depressed andlocked position. Again a resilient mechanism 11 is attached to theholding plate 4. Leaf springs 17 are attached to the edge of the opening6 opposite the edge which engages the catch 10. The springs are inclinedat an acute angle below the holding beam 4 such that depressing of theoperative push button 8 will cause the cam surface 14 of the controlelement 7 to engage the spring 17. The cam surface 14 in this embodimentis the narrow side of the control element 7 opposite the catch 10. Oncethe spring force of spring 17 overcomes the resistance of the tensionspring the holding beam 4 will move to the left as shown in FIGURE 2.This movement of the holding beam 4 will cause the beam to overlay thecatch and thereby lock the push button 8 in the depressed position.Again, the other non-depressed push buttons 8 are blocked by theinterference between the holding beam 4 and the extension 16 of thecontrol element 7. If several push buttons 8 are to be depressed thismust be accomplished simultaneously.

For releasing depressed push buttons, the holding beam in thisembodiment comprises an inclined projection 18 with which controlelement 7 of the release push button 9 cooperates. The holding beam isagain moved in the direction of its rest position until the depressedpush buttons are released and the corresponding resilient elements 17are relaxed whereby the holding beam returns to its rest position underthe action of the tension spring 5.

As may be seen from the above embodiments, particular requirements neednot be imposed upon the dimensions of the recesses 6 and the holdingbeam 4 and the catches and locking members 10, 16 on the push buttoncontrol elements, since the resilient elements 11 have a compensatingeffect. Snapping into engagement and locking, respectively, of the keysis also ensured after a prolonged period in operation.

Variations of the embodiments described are possible without departingfrom the scope of this invention. For example, the push buttons may besliding push buttons or swinging push buttons, several release pushbuttons may be provided of which some have separate holding devices andthe like. There are not any limitations on the designer in constructingthe resilient elements, the holding beam and the push button controlelements; for example, the locking member may also be formed by thelower side of the control elements or the resilient elements may bearranged on the control element instead of on the holding beam. Thecontrol element is to be understood to include also members which can bemoved in a direction other than the direction in which the push buttonsare operated.

What is claimed is:

1. A push button mechanism for recording and playback apparatus,comprising a series of operative push buttons, support means forretaining said push but-tons, means connected to said support means forengaging an operative push button in an actuated position, first meansattached to said engagement means for biasing said engagement means to anon-engaging position relative to said operative push button, catchmeans on said operative push button adapted to lockingly engage saidengagement means when said operative push button is actuated, secondmeans attached to said engagement means and upon actuation by saidoperative push button normally biasing said engagement means to alatching position relative to said operative push button against theaction of said first biasing means thereby to engage said catch meansand engaging means, and release push button means actuating saidengagement means to override said second biasing means thereby todisengage said engagement means from the catch means of said operativepush button.

2. A ush button mechanism according to claim 1 wherein said at least oneoperative push button includes a control element having the catch meansattached thereon, said engagement means comprising a holding beampositioned normal to the longitudinal axis of said operative push buttonand in spaced relation from said catch means, one opening in saidholding beam for each operative push button to receive said catch means,said second biasing means being positioned adjacent one edge of saidopenings, whereby actuation of said push button of said operative pushbutton causes said control element to engage said second biasing meansthereby causing said holding beam to move from its normally biasedpositioned into locking engagement with said catch means.

3. A push button mechanism according to claim 1 wherein said operativepush button includes means to preclude actuation of the remainingoperative push buttons after at least one operative push button has beenactuated and lockingly engaged said engagement means.

4. A push button mechanism according to claim 2 wherein said releasemeans comprises a release push button having cam means thereon, saidrelease push button being retained in said support means, and camengaging means on said holding beam whereby actuation of said releasepush button will move said cam means into engagement with said camengaging means thereby forcing the holding beam out of lockingengagement with said operative push button.

References Cited UNITED STATES PATENTS 2,451,150 10/1948 Brian 74483 XR2,558,113 6/1951 Walton 74-483 2,973,664 3/1961 Williams 74-483 FRED C.MATTERN, JR., Primary Examiner.

B. T. CALLAHAN, Assistant Examiner.

